1. Field of the Invention
The present invention relates to an airbag device for a front passenger seat whose airbag is deployable for catching a passenger (especially, his head) seated in a front passenger seat not only in the event of a frontal collision of a vehicle at which the passenger moves forward, but also in the event of an oblique collision of a vehicle at which the passenger moves diagonally forward in a left and right direction such as towards a driver's seat or towards an outboard direction.
2. Description of Related Art
JP S56-67649 discloses a known airbag device for a front passenger seat which includes in an airbag, in addition to a main bag section inflatable in front of a passenger seated in a front passenger seat, an auxiliary bag section (a center bag section) which is partitioned from the main bag section by a partition wall and is inflatable in front of a space between the front passenger seat and driver's seat. In this airbag, the rear face of the auxiliary bag section is flush with that of the main bag section along a left and right direction such that the airbag may restrain a passenger seated in a center seat disposed between the driver's seat and the front passenger seat. Further, the partition wall is provided with a check valve for allowing a gas flow into the auxiliary bag section and preventing a pressure plunge of the auxiliary bag section.
JP H2-303951 discloses an airbag device for a front passenger seat with an airbag which includes at an end region of its rear face at a side of the driver's seat an protruding section for catching the head of a passenger seated in the front passenger seat in the event of an oblique collision, such that the airbag cushions the passenger not only in the event of a frontal collision but also in the event of an oblique collision (including also an offset collision not only an instance where a vehicle crashes while moving diagonally forward).
However, the conventional airbag devices for a front passenger seat cannot catch a passenger (especially, his head) moving diagonally forward at oblique collision in an adequate fashion without turning the face of the passenger towards an outboard direction or an inboard direction.
That is, the airbag disclosed in the former reference has merely an increased volume on a side of the driver's seat and cannot catch a passenger without turning the passenger. The airbag disclosed in the latter reference is able to prevent the passenger's head from turning by the protruding section at cushioning to some extent. However, if the protruding section is deformed in such a manner as to fall down towards the driver's seat after cushioning the head, the protection will not be sufficient.